<html lang="zh-cn">
  <header>
    <style>
      .container {
        background-color: aquamarine;
        overflow: hidden;
        /* 这里的overflow: hidden;可以让container元素正常拥有高度，以前都用clear:both清除浮动来着 */
      }
      .item {
        width: 120px;
        height: 200px;
        background: lightblue;
        margin: 20px;
        float: left;
      }
    </style>
  </header>
  <body>
    <div class="container">
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
      <div class="item"></div>
    </div>
  </body>
</html>
